Tube-pointing machine



May 10, 1966 COPPER ET AL 3,250,110

TUBE-POINTING MACHINE 2 Sheets-Sheet 1 Original Filed Aug. 9, 1963 s d wwm w W 0 m [mm m VPH A N013 my T g Rs 5 WM \MRM May 10, 1966 C P ET AL 3,250,110

TUBE-POINTING MACHINE Original Filed Aug. 9, 1963 2 Sheets-Sheet 2 Eli-=7 ROBERT L. COPPER and JAMES M HOUSHOLDER FILE-=3 tor/76y United States Patent 3,250,110 TUBE-POINTING MACHINE Robert L. Copper, Wayne Township, Lawrence County,

and James V. Housholder, Ellwood City, Pa.,"assignors to United States Steel Corporation, a corporation of Delaware Original application Aug. 9, 1963, Ser. No. 301,149.

Divided and this application Mar. 11, 1965, Ser.

Claims. (Cl. 72411) The present application is a division of our application Serial No. 301,149, filed August 9, 1963.

The invention relates to an improved apparatus for forming a point on the end of a tube preliminary to a cold-drawing operation.

A conventional cold-drawing operation, as applied to metal tubes, involves pulling the tube through a die which encompasses the exterior. Usually a mandrel is inserted in the tube bore to support the inside of the tube and control the size of the hole, although in a sinking operation no mandrel is used. Initially the outside diameter of the tube is larger than the die opening Hence it is necessary beforehand to form a point on the end of the tube. The pointed end is pushed through the die opening and gripped to pull the rest of the tube through. The most common practice is to form the point in a hot-forging operation, which is time-consuming and costly. Machines are known for collapsing the end of a cold tube to form a point, but such machines have not been gone into extensive use. Previous machines often produce a crooked point or a bulge in the tube next to the point. Defects of this sort interfere with the drawing operation.

The principal object of the present invention is to provide an improved pointing machine which produces properly shaped points on cold tubes.

A further object is to provide an improved pointing machine adapted to be installed in a drawbench for forming points on tubes after they actually reach the drawbench, thus eliminating extra processing and handling steps.

In the drawings: 1

FIGURE 1 is a rear elevational view of our pointing machine;

FIGURE 2 is' an end elevationalview of our pointing machine;

FIGURE 3 is anapproximately vertical sectional view of our pointing machine taken on line IIIIII of FIG- 'URE 1;

FIGURE 4 is an approximately horizontal sectional view of the die embodied in our machine taken on line IV-IV of FIGURE 3;

FIGURE 5 is a diagrammatic end elevational view of our punch and die showing one step in forming a point on a tube;

FIGURE 6 is a view similar to FIGURE 5, but showing a subsequent step; and

FIGURE 7 is an end elevational view of a tube which has a fiinshed point formed thereon.

Our pointing machine includes a base 33 rigidly attached to a framework 29, which can be part of a conventional drawbench. Tubes arriving at a drawbench commonly slope downwardlytoward one end. When our machine is installed in a drawbench, base 33 slopes at the same angle as the tubes. As best shown in FIGURE 3, an upright C-shaped frame 34 is rigidly fixed to base 33 and is open at the back to permit tubes to enter as they travel sideways. Frame 34 carries opposed guides 35 which extend upwardly at right angles to base 33. We mount a die carriage 36 on guides 35 and a double-acting fluid pressure cylinder and piston 37 on the top of frame 34 operatively connected with the die carriage for raising 3,250,110 Patented May 10, 1966 and lowering it. Frame 34 also carries a stationary upstanding punch 38, and carriage 36 carries a cooperating movable die 39, the details of which are described more fully hereinafter. Both the punch and die are removably mounted, whereby they can be changed-for different sizes. As best shown in FIGURE 1, one end of the die carriage 36 carries a bracket 40 on which we mount a guide 41 and an ejector 42. The ejector can be simply a doubleacting fluid pressure cylinder and piston with a pin fixed tothe end of the piston rod, and we have not shown it in detail. One end of frame 34 carries a bracket 43 to which we pivot a bell crank 44. We journal a grooved idler roller 45 to one arm of the bell crank, and we connect a double-acting fluid pressure cylinder and piston 46 between the other arm and the upper portion of frame 34. When this cylinder is operated, the bell crank turns to raise or lower roller 45. When the roller is raised, it

38 and die 39.

clears tubes T to enable them to enter the back of the pointing machine. When the roller is lowered, it is positioned to engage the top of a tube.

In operation, as each tube T arrives at the machine, it enters the back, where it rests on guide 41 and overlies punch 38. We lower roller 45 into engagement with the tube to hold the tube accurately in alignment with punch Next we move the tube lengthwise until it reaches a position in which its end portion is directly over the punch, and we stop it in this position. We operate cylinder 37 to lower the die carriage 36 and die 39.

This action collapses the end portion of the tube to form a point thereon. We again operate cylinder 37, but in the opposite direction to raise the carriage and die. We operate the ejector 42 to force the pointed end portion of the tube from the die and reset the ejector. Thereafter the tube resumes its lengthwise travel, and the operation proceeds as in conventional practice.

FIGURES 4, 5 and 6 illustrate the action of our punch 38 and die 39 in more detail. a The punch and die are elongated and are of a length equivalent to the length of point desired on the tube (FIGURE 4). The upper face of the punch is concave to engage the bottom of the tube (FIGURES 5 and 6). The die opening faces downwardly and has a tapered entrance portion 47 at the bottom, a straight-sided tube-flattening portion 48 extending upwardly therefrom, and a bulbous. tube-expanding portion 49 at the top. The tube-expanding portion 49 tapers toward the right; the left end has a bell-shaped mouth 50 (FIGURE 4). When each tube T stops, its end portion lies immediately above the concave upper surface of punch 38. As die 39 descends, it first flattens the tube to an oval shape as shown in FIGURE 5. Next the tubeexpanding portion moves over the upper end of the oval, as shown in FIGURE 6, and effectively collapses the vertical column sections formed by the sides of the oval. Continued descent of the ,die folds the material inwardly and forms a point of the configuration shown in FIGURE 7. The bell mouth 50 is important as a means for preventing a bulge in the tube back of the point. A bulge would interfere with the desired processing of the tube as it passes through the die stand of the drawbench. The taper aids in releasing and ejecting the tube from the die. The point should be substantially concentric with the rest of the tube to assure that the tube is drawn in a straight line through the die stand. Our machine accurately aligns the tube with the punch and die to obtain the necessary conc'entricity. It is also essential that the point does not completely close the end of the tube. Otherwise air is entrapped between the end of the mandrel and the 3 machine of course can be actuated manually, but the machine is adapted for automatic actuation. When the machine operates automatically, the end of base 33 opposite bracket 43 carries another bracket 51 on which we mount a flag switch 52. As best shown in FIGURE 3, we mount an upstanding bracket 53 on base 33 and a light source 54 on said bracket. We mount a photocell 55 on frame 34 in alignment with the light source 54. The frame has an opening 56 to admit light from source 54 to the photocell. The light source is positioned,

below the path of tubes as they move sideways into the pointing machine in order not to interfere. As each tube enters the pointing machine, it depresses the flag switch 52, and it interrupts the light beam, from the source 54 to photocell 55. As the tube travels lengthwise, its end releases the flag switch and shortly thereafter exposes photocell 55 to the light source 54. The resulting energization of the photocell signifies the tube has reached the proper positioning for pointing.

Operation of the flag switch 52 sets up a control circuit and energization of the photocell 55 triggers this circuit, which stops the tube and operates cylinder 37. The subsequent steps in the operation of our machine can be initiated by opening and closing of appropriate limit switches (not shown) as different operations take place. The control circuit embodies conventional relays (not shown) which are energized and deene'rgized as the limit switches open and close.

From the foregoing description it is seen that our invention affords a simple mechanism for forming properly shaped points on cold tubes, preferably after they reach a drawbench. The pointing operation can be automatic to the extent that the operator performs no more manual steps than he does in conventional drawbench operation. The die configuration enables the machine to point relatively heavy wall tubes with minimum hydraulic pressure.

While we have shown and rescribed only a single embodiment of the invention, it is apparent that modifications may arise. Therefore, we do not wish to be limited to the disclosure set forth but only by the scope of the appended claims.

We claim:

1. A machine for forming a point on the end of a tube comprising a frame open at the back to permit tubes to enter as they travel sideways, an elongated punch carried by said frame and having a concave tube-engaging surface, a cooperating die carried by said frame, said die having an opening adapted to receive said punch and a tube engaged thereby, said opening including in succession a tapered entrance portion, a straight-sided tubefiattening portion, and a bulbous tube-expanding portion, said tube-expanding portion having a bell-shaped mouth, and means on said frame for producing relative movement between said punch and said die.

2. A machine for forming a point on the end of a tube comprising a C-shaped frame open at the back topermit tubes to enter as they travel sideways, an elongated upstanding punch fixed to the lower portion of said frame and having a concave tube-engaging upper face, guides carried by said frame, a die carriage supported on said guides, 21 die mounted on said carriage and having a downwardly facing opening to receive said punch, said die opening including in succession a tapered entrance portion, a straight-sided tube-flattening portion, and a bulbous tube-expanding portion, said tube-expanding portion having a bell-shaped mouth, and fluid pressure means mounted on the top of said frame and operatively connected with said carriage for raising and lowering said die relative to said punch.

3. A machine as defined in claim 2 further comprising a roller, and means pivoted to said frame on which said roller is journaled, said roller having a raised position in which it clears tubes as they travel sideways and enter the back of said frame, and a lowered position adapted to engage the top of a tube as it travels lengthwise between said punch and said die for holding the tube in proper alignment.

4. A machine for forming a point on the end of a tube comprising a C-shaped frame open at the back, an elongated upstanding punch fixed to the lower portion of said frame and having a concave tube-engaging upper face, guides carried by said frame, a die carriage supported on said guides for movement up and down, a rearwardly extending guide supported on said carriage for directing a tube as it travels sideways into the open back of said frame and onto the upper face of said punch, a die mounted on said carriage and having a downwardly facing opening to receive said punch, said die opening having an upwardly tapered entrance portion at its lower end, a straight-side tube-flattening portion extending upwardly from said entrance portion, and a bulbous tube-expanding portion having a bell-shaped mouth, fluid pressure means mounted on the top of said frame and operatively connected with said carriage for raising and lowering said die relative to said punch, and an ejector supported on said carriage opposite said bell-shaped mouth for pushing a pointed tube endwise from said die.

5. A machine as defined in claim 4 further comprising a bracket on said frame opposite said second-named guide, a bell-crank pivoted to said bracket, a roller journaled on one arm of said bell-crank, and means connected to the other arm of said bell-crank for raising and lowering said roller, said roller having a raised position in which it clears a tube as it travels sideways in entering the open back of said frame and a lowered position to engage the top of a tube as it travels lengthwise between said punch and said die for holding the tube in proper alignment.

References Cited by the Examiner UNITED STATES PATENTS 810,241 1/1906 Winstrom 153-70 3,068,929 12/1962 Rowell 153-34 3,144,070 8/1964 Mieszcak 15334 FOREIGN PATENTS 816,688 10/1951 Germany.

RICHARD J. HERBST, Primary Examiner. 

1. A MACHINE FOR FORMING A POINT ON THE END OF A TUBE COMPRISING A FRAME OPEN AT THE BACK TO PERMIT TUBES TO ENTER AS THEY TRAVEL SIDEWAYS, AN ELONGATED PUNCH CARRIED BY SAID FRAME AND HAVING AN CONCAVE TUBE-ENGAGING SURFACE, A COOPERATING DIE CARRIED BY SAID FRAME, SAID DIE HAVING AN OPENING ADAPTED TO RECEIVE SAID PUNCH AND A , TUBE ENGAGED THEREBY, SAID OPENING INCLUDING IN SUCCESSION A TAPERED ENTRANCE PORTION, A STRAIGHT-SIDED TUBEFLATTENING PORTION, AND A BULBOUS TUBE-EXPANDING PORTION, SAID TUBE-EXPANDING PORTION HAVING A BELL-SHAPED MOUTH, AND MEANS ON SAID FRAME FOR PRODUCING RELATIVE MOVEMENT BETWEEN SAID PUNCH AND SAID DIE. 